<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    /* 整个滚动条 */
    ::-webkit-scrollbar{
      width: 15px;
      background-color: #ccc;
    }
    /* 滚动条滑块 */
    ::-webkit-scrollbar-thumb{
      border-radius: 40px;
      background-color: aqua;
    }
    /* 滚动条滑轨 */
    ::-webkit-scrollbar-track{
      background-color:blanchedalmond;
    }
    /* 滚动条按钮 */
    ::-webkit-scrollbar-button{
      height: 20px;
      background-color: orange;
    }
  </style>
</head>
<body>
  <div style="height: 2000px;"></div>
</body>
</html>